Suction apparatus on a textile machine

ABSTRACT

A suction apparatus for picking up the free end-portion of a thread on a textile machine wherein the thread is brought into a freely stretched condition over a suction means and is drawn into this means by a suction action, said apparatus comprising a thread-holder located on the suction means, said holder comprising clamping zones that are biassed towards each other for clamping a thread therebetween and guide means for guiding the end-portion of the thread towards the clamping zones; and means for pulling the end-portion of the thread, drawn into the suction means, in between the clamping zones.

O United States Patent 1151 3,665,976 Freihofer 45 May 30, 1972 [54]SUCTION APPARATUS ON A TEXTILE [56] References Cited MACHINE UNITEDSTATES PATENTS 1 lnvemofl Alexis Frelhofer, Rmi/ZH, Switzerland2,956,593 /1960 Baumann ..139/247 3,233,636 2/1966 Bulcock ....l39/256[73 1 Ass'gnee' :i: g g wwks Run/2H 3,417,793 12/1968 Freihofer.... 1 39194 Ze 3,494,151 2 1970 Baker et al ..66/140 s [22] Filed: June 29, 1970Primary Examiner-Henry S. Jaudon PP 50,722 Attorney-Donald D. DentonForeign Application Priority Data [57] ABSTRACT A suction apparatus forpicking up the free end-portion of a July 22, 1969 Switzerland ..01 l162 thread on a textile machine wherein the thread is brought into afreely stretched condition over a suction means and is drawn [521' US.Cl ..l39/ 126 i hi means b a suction action, said apparatus comprising[51] Int. Cl. ..D03d 47/24 a thread-holder located on the suction means,said holder [58] Field of Search ..l39/122, 125, 126, 246, 247,comprising clamping zones that are biassed towards each 139/256 R, 256A; 194, 257; 242/ 35.6 E; 66/ 140 S, other for clamping a threadtherebetween and guide means for 145 S guiding the end-portion of thethread towards the clamping zones; and means for pulling the end-portionof the thread, drawn into the suction means, in between the clampingzones.

17 Claims, 5 Drawing Figures mnm-lgim Patented May 30, 1972 3,665,976

5 Sheets-Sheet 2 Patented May 30, 1972 5 Sheets-Sheet 5 Fig.4

lllllll'l SUCTION APPARATUS ON A TEXTILE MACHINE BACKGROUND OF THEINVENTION This invention relates to an apparatus on a textile machine,e.g., a loom, for picking up the loose end-portion of a thread, which ismoved in a freely extended condition over a suction means of theapparatus and is drawn into the suction means by the suction of saidmeans.

This type of thread operation takes place for example during weavingwhen the loose end of a weft-thread is released from a shuttle after thepassage of the shuttle through a shed and the loose end is transferredto a suction means in the form of a nozzle. After this transfer, theweft-thread is often withdrawn somewhat prior to beating up at thebeat-up of the fabric so that it is in a neatly stretched position forthe beat-up. Since it is desirable to keep the thread-ends drawn in bythe suction nozzle as short as possible, it is found that when thethread is pulled back for the purpose of bringing it into a stretchedcondition, the thread is not retained in the suctionnozzle with thenecessary reliability and firmness. This is observed in particular whenthreads of different kinds are used.

Advantageously, this invention provides an apparatus for overcoming thisdraw-back. Thus, the present invention provides a suction apparatus orsuction-nozzle arrangement, having additional means for retaining thethread which are extremely reliable even when different kinds of threadare being handled.

For the purpose of pulling off the end-tum portion of a thread from abobbin in the automatic changing of bobbins, it is known to provide asuction-nozzle which is covered by a flap when the end-tum is located inthe interior of the suctionnozzle. In this arrangement, the flap acts asa clamp or brake for the thread. On account of the flap being adapted tomove over the suction-nozzle and away from it again, this knownarrangement is suitable only for certain applications, in particular theafore-mentioned pulling off of the end-tum. This arrangement cannot,however, be used for taking over the end of the thread from a movingshuttle or the like.

This invention contemplates a suction apparatus which is characterizedin that a thread-holder means is positioned on a suction means, thethread-holder means comprises clamping zones that are biassed towardseach other and are used to clamp a thread, guides are provided forguiding the end-portion of the thread towards the clamping zones, andmeans are provided for the purpose of drawing the end-portion of thethread, sucked into the suction-nozzle, in between the clamping zones.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described inmore detail by reference to its specific embodiments and to theaccompanying drawing, in which:

FIG. 1 is a schematic illustration of a loom having means for insertingweft-threads, wherein use is made of the suction apparatus of thepresent invention;

FIG. 2 is an end view of a suction-nozzle in the apparatus of theinvention used as seen in the longitudinal direction of its suctionorifice;

FIG. 3 is a side view of the nozzle shown in FIG. 2 as viewed on thenarrow side in the direction of the arrow III;

FIG. 4 is a view of another embodiment of the suction-nozzle arrangementof the invention wherein an auxiliary suctionnozzle is employed; and

FIG. 5 is a detail side-view, on a larger scale, of the end of theauxiliary suction-nozzle seen in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustratesschematically an embodiment of a weft-insertion means in a loom, thesuction-nozzle arrangement of the present invention being used with thismeans. The reference numerals l1 and 12 indicate large weft-threadsupply bobbins arranged on both sides of the frame of the loom. Fromthese bobbins the threads 13 and 14, respectively,

run through the rings 15 and 16, the thread-braking devices 17 and 18and additional thread guides 19 and 20 (all of which elements aresecured to the frame of the loom.) In FIG. 1, the thread 13 terminatesin the suction-novJe or retaining nonle 21, which constitutes athread-retaining means, whereas the thread 14 passes along thecorresponding suction-nozzle or retaining nozzle 22, which alsoconstitutes a thread-retaining means, and through the pull-backarrangement 48, 49. The retaining suction-nozzles 21 and 22 are mountedon the frame of the loom. To make the drawing easier to understand, onlythe warp-threads 23 at the sides of the fabric are shown, and not theentire group. The thread 14 extends through the shed formed by thewarp-threads 23, and its free end is retained by the suction-nozzle 25.The suction-nozzle on the left-hand side which corresponds to nozzle 25is indicated by the reference numeral 26. The nozzles 25 and 26 arearranged on the movable sley 30 and move relatively thereto in adirection at rightangles thereto (forwards and backwards as shown by thedashdot lines). Located on the sley 30 is the shuttle 31 used as athread positioning or locating element or means for inserting theweft-threads into the shed. The shuttle 31 incorporates an element madeof ferromagnetic material, e.g. iron, which element is positioned intothe lower slide surface of the shuttle. The shuttle also contains twohorizontal orifices 43 and 44 extending laterally therethrough. Meansfor retaining the weft-thread during its insertion into the shed areprovided in these orifices. These means can, for example, comprisebristles which are able to retain a thread disposed therein by applyinga predetermined force to the thread. It is possible nevertheless towithdraw the thread from the shuttle 31, i.e. the predetermined force isless than the breaking strength of the weft-thread (i.e. threads 13 and14).

The reed 32 is secured to the sley 30. Furthermore, in the sley thereare provided magnetic control arrangements 33 and 34, the electricalproperties of which can be varied by a ferromagnetic material. In thepresent embodiment, each of the arrangements 33 and 34 comprises apermanent magnet surrounded by a wire coil. These magnets are U-shape(i.e. they are horse-shoe magnets) and are incorporated in the sley 30in such a manner that their poles are upwardly directed, (i.e. themagnet forms an upright U). The ferromagnetic element 35, which moveswith the shuttle, produces a change in the magnetic flux in the magneticarrangements 33 and 34. Thus, when the shuttle 31 with the ferromagneticmaterial 35 fitted at its underside, moves over the arrangements 33 and34, a voltage variation in the coils is produced.

On both sides of the loom there are also provided pull-in devices 36 and37 incorporating, respectively, the hooks 41 and 42. These devices areadapted to rotate about the spindles 38 and 39 carried by the sley 30,and are used for pulling the weft-threads l3 and 14, respectively, intothe shuttle 31. This pull-in action takes place when, during themovement of the sley into the foremost position, i.e. the thread beat-upposition, each of the rollers on the two sides (indicated by the samereference numeral 27) moves over the projecting portion 28 of a carnmedsurface and thereby swings the hook 41 about the spindle 38 in theanti-clockwise direction, and the hook 42 about the" spindle 39 in theclockwise direction. The thread-guides 19 and 20 are controlled in suchmanner that they only pass the thread that they hold to the hooks 41 and42, respectively, when the shuttle 31 is located at their side of theloom. The reference numerals 45 and indicate two pairs of shears forcutting off the weft-threads 13 and 14, respectively. The thread-brakingdevices 17 and 18 each incorporate a thread-clamp 46 and 47, and theseclamps are each actuated by a controllable magnet. Finally, a threadpullback means including elements 48 and 49, is provided on each side ofthe loom.

In the phase of operations shown in FIG. 1, the shuttle 31 has justarrived from the left at the right-hand side of the loom. The thread 14,inserted by the shuttle during its flight, has been braked by the clamp47 of the braking device 18 and thus pulled out of the shuttle 31 afterthe shuttle has moved over the magnetic arrangement 33 and the magnet ofthe braking device 18 has been supplied with current so as to close thisdevice. The supply of current to the magnet of the device 18 wascontrolled by a signal which was produced by the ferromagnetic element35 during the flight of the shuttle 31 over the arrangement 33. As shownin FIG. 1, the pulled out end of the thread 14 has been drawn in andretained by the nozzle 25. During this entire operation, the magnet ofthe braking device 17 on the right-hand side has been supplied withsufiicient current to cause closing of the clamp 46.

In the course of further operation of the loom, the thread pull-backmeans (48 and 49) on the left-hand side of the loom pulls back thethread 14 a little by means of the hook 48 so that the thread is neatlystretched when the reed 32 beats up the pulled-in thread 14. The shedcomprising the warp-threads 23 is then changed. The shears 45 and 40 cutoff the weftthread 14 at the two edges of the fabric. At this moment thesuction-nozzle 26 is not at the same level as the fabric beat-up zone,but is moved forward away from this zone and therefore also away fromthe thread 14, i.e. away from the sley 30. The end of thread thatbecomes free on the left-hand side when cutting takes place is thereforedrawn into the retaining nozzle 22. The short thread-end hanging in thethread-transfer nozzle 25 must be drawn away.

In the foremost position of the sley 30, the pull-in hook 41 rotates inthe counter-clockwise direction and is moved through the horizontalorifice 44 into the shuttle 31. When the sley 30 moves back again, thehook picks up the thread 13, presented by the thread-guide 19, and,since the clamp 46 is closed, draws the thread out of thethread-retaining means provided by nozzle 21 and pulls it as a loopthrough the orifice 44 in the shuttle 31. The movement of the pull-indevice 37 that occurs at the same time is not important, since thiscannot transfer a thread through the thread-guide 20. When the shuttle31 is shot to the left immediately thereafter, the weftthread 13 is heldby a weft-retaining means contained in the orifice 44 and, since theclamp 46 opens at this moment, the thread is drawn off from the supplybobbin 11 and introduced into the shed. An operation similar to thatjust described is then repeated, but on the other side of the loom.

As already mentioned, the suction-nozzles 25 and 26, constituting thethread transfer devices or means, are carried by the sley 30 and arealso movable at right-angles to the longitudinal direction of the sley.Thus, as the shuttle 31 moves through the loom and past thesuction-nozzle 25 or 26, these nozzles can be moved relatively to thesley 30 into a position such that the fabric-side or forward sidesurface of the shuttle 31 moves directly past the orifice of thesuction-nozzle 25 or 26. The end of the thread drawn out of the shuttle31 is thus picked up in a reliable manner. Additionally, the nozzles 25and 26 can be moved away from the weft-threads 13 and 14 when thesethreads, as described above, are taken over by the retaining nozzles 21and 22 after they have been cut off.

When the weft-thread 14 is pulled back by means of the lefthand hook 48,part of the thread drawn into the suction-nozzle 25 is pulled out of itagain. Since the losses of thread should be kept as low as possible,care is taken to see that the thread-end remaining in the nozzle 25 isas short as possible. The suction applied by the nozzle 25 to the thread14 therefore becomes relatively small. It can be so small that thethread 14 can jump out of the nozzle 25.

To prevent this, and in accordance with the present invention, thenozzle 25 (and the nozzle 26) can be constructed, for example, in themanner seen in FIGS. 2 and 3. These figures are on a greater scale.

The end of nozzle body 50 forms an orifice or opening 51 and has at thetop a small plate 52 and a small plate 53. The plate 53 is bonded orotherwise secured to the noule body 50. The plate 52 is attached to thecarrier 54 by screws 58 and is supported by said carrier. The carrier 54is in turn secured to the nozzle body 50 by screws 55. The boundary oredge portion 62 of plate 52 and the boundary or edge portion 63 of plate53 cross at the point of intersection 60. They form an acute angle witheach other and each one constitutes a guide for the thread 13 or 14.

The plate 52 is made of ferromagnetic material and is continuouslypulled by the magnet 56 which is inserted in the nozzle body 50. Thisresults in a zone (located on the right-hand side of the point ofintersection 60 in FIG. 2) in which portions of the plates 52 and 53bear against each other and are constantly biassed towards each other toprovide a thread holding means, or thread holder device. This zone isbounded by the solid line 66 defining the lower edge of plate 52 and thebroken line 67 defining the upper portion of plate 53. Since the threadto be drawn into the suction nozzle 25 is guided by the boundaryportions 62 and 63 towards the point of intersection 60, these boundaryportions 62 and 63 form guide arms or surfaces which diverge from eachother beginning at the area where the plates 52 and 53 bear against eachother. By pressing on the area 57, indicated in FIG. 2 by the brokenline, the plate 52 can be tilted about the edgeportion 59, so that thezone of the plate 52 which bears on the plate 53 is lifted somewhat fromthe plate 53 thereby overcoming the bias provided by the magnet 56. Thisresults in the release of the end portion of thread held between theseplates 52 and 53 and this end portion can be drawn into the nozzleopening 51 by the flow of air.

In order to take over the end of a thread inserted by the shuttle 31, anozzle 25 as already mentioned, is brought into the direct vicinity ofthe forward side-wall of the shuttle 31 when the shuttle 30 moves fromleft to right. By means of the clamp 47, the weft-thread 14 is retainedat an appropriate moment. This is so selected that the thread-end, drawnfrom the shuttle 31 or located thereby so it, extends over the greaterpart of the nozzle opening 51 or even slightly beyond the nozzle 25before it is drawn into the nozzle. Since FIG. 2 shows a view of thenozzle 25 in the direction of its opening, the thread-end, indicated bythe reference numeral 64, extends in this Figure from right to left.Immediately after the thread 14 has been drawn out of the shuttle 31,and before it is drawn into the nozzle 25, it stretches out in front ofthe noule 25 for a short moment in a straight line i.e. parallel with astraight line which lies within the acute angle formed by the boundaryportions 62 and 63 and which runs through the point of intersection 60.When the end-portion 64 of the thread is drawn into the nozzle opening51, the boundary portions 62 and 63 act as guides for the end-portion 14of the thread and guide it to the point of intersection 60. It thenpasses downwards from the point of intersection 60.

The thread is thereupon drawn back a little through the pull-back deviceof means 48, 49 shown on the left in FIG. 1, by this device moving inthe direction of the arrow 61 shown in FIG. 1 and into the position asshown in this Figure. Thus, the thread 14 is stretched out neatly in theshed. At the same time part of the length of the thread-end 64 is againdrawn out of the opening 51. During this operation, the thread-portion64 slides between the contiguous zones of the plates 52 and 53, definedby the boundary or edge portions 66 and 67, and moves into the positionindicated by the numeral 64 in FIGS. 2 and 3, in which position it isclamped therebetween as a result of the bias imposed by the magnet 56.

It will be recognized that the weft-thread is retained in a veryreliable manner by the suction arrangement illustrated. The retainingforce resulting from the clamping action is independent of the length ofthe thread-end 64 and is considerably greater than the force resultingfrom the suction effect. In particular this greater retaining force isalso present when different kinds of weft material are being worked.

If the weft-thread is elastically extensible, it is hardly possible,without the provision of the clamping zones of this invention to preventthe end-portion of the thread from springing back and jumping out of thenozzle after it has been released from the shuttle. Here it is ofparticular advantage that as a result of a pull on the thread this ismoved into and between the clamping zones, so that simply because of itselastic contraction it is moved in between the clamping zones. Apullback arrangement 48, 49 is not absolutely necessary in thesecircumstances.

If the boundary portions 62 and 63, acting as guide-arms or guide means,form anacute angle with each other, the size of which correspondsapproximately to that shown in FIG. 2, slip of the thread-end 64 isreliably ensured between the zones of mutual contact defined by theboundary portions 66 and 67, i.e. between the superposed zones of theplates 52 and 53. In order to provide a wider safety margin forslip-through, one or both of the boundary portions can be bentimmediately in front of the point of intersection 60 in a direction suchthat the angle at said point of intersection 60 becomes still moreacute. This is the case with the boundary portion 63 seen in FIG. 2.

After the weft has been beaten up, the weft-thread 14 is cut on bothsides of the loom by the shears and 45. The resultant free end is drawninto the retaining nozzle 22 on the left-hand side of the loom. On theright-hand side of the loom, the cut-off thread-end remains firmly heldin the suction-n02 zle 25.

If, as in the embodiment in question, the suction apparatus orarrangement operates on a continuous basis, then for the apparatus tooperate correctly, i.e. for the next thread-end to be properly pickedup, it is necessary that each clamped thread-end is removed again beforethe new thread-end is picked up.

Therefore, when, during the further course of the operation of the loom,the sley is moved backwards, the apparatus strikes a spring-loaded pin65 in the rearmost position of its zone 57. This causes the plates 52and 53 to be moved apart somewhat in the zones defined by portions 66and 67 where they bear against each other. In this condition, thethread-end 64, held by the nozzle 25, is drawn into said nozzle.

A method of removing the thread-end 64 held in the nozzle 25, based on asomewhat different mode of operation, will be explained by reference tothe embodiment shown in FIGS. 4 and 5. FIG. 4 shows the right-hand sideof the loom together with the warp-threads 23, the sley 30 and themagnetic control arrangement or electrical sensing means 33. Thesuction-nozzle 25, the weft-thread pull-back device or means 48 and 49,

and the retaining nozzle 21 are again of the same construction as thatalready described. This also applies as regards the cutting means 45,but with the difference that this cutting means, in contrast to thatshown in the embodiment of FIG. 1, makes a cut only after each secondweft-insertion. Between the suction-nozzle 25 and the shed formed by thewarpthreads 23, there is provided another suction means in the form of asecond suction-nozzle or auxiliary suction-nozzle 70. That side of thisnozzle facing the suction-nozzle 25 incorporates a threader means, whichis formed by appropriately shaping the wall of the nozzle. The nozzle 70is mounted on the frame of the loom. The shape of this threader means 71is shown in side-view in FIG. 5.

After the nozzle 25 has drawn in the end-portion 64 of the thread 14from the shuttle 31, and the thread 14 has been pulled back by thepull-back device 48 and 49 located on the left-hand side of the loom, sothat the thread is firmly held in the nozzle 25, the nozzle 25 movesfarther forward, ie in the direction of the arrow 61. The end-portion 64of the thread is thereby also drawn forward as shown in FIG. 4. Thisend-portion 64 of the thread slides along the curve portions 72 or 73 ofthe threader and passes into the cut-away zone 74. When, thereupon thenozzle 25 moves to the rear again, a pulling force occurs on thethread-portion 64 between the thread 14, now beaten-up and woven intothe fabric, and the nozzle 25, since the nozzle 70 remains stationaryand the end-portion of the thread is retained in the cut-away portion74. Therefore, despite the fact that it is clamped between the plates 52and 53, the end-portion 64 of the thread is pulled out of these platesand out of the nozzle 25. As soon as the thread is free of the noule 25,it is drawn completely into the nozzle 70. After the next weft-thread 13is inserted into the shed, the weftthread 13 and the thread-end drawninto the nozzle 70 are simultaneously cut. The cut thread-end 64 drawninto the nozzle 70 is thus removed therethrough.

When removing the end-portion 64 of the thread by the method describedby reference to FIG. 1 and in which the plate 52 is lifted somewhat fromplate 53 due to striking the pin 65, it can occasionally happen that thethread-portion 64 remains hanging. In such circumstances the nextend-portion of thread to be picked up is held with too little retainingforce or is not held at all. If, in addition, the weft-threads areinspected in the interior of the nozzle 25, the hanging end-portion ofthread gives the incorrect impression that a weft-thread is present.These disadvantages are eliminated by the method of and apparatus forremoving the end-portions 64 of thread described in reference to FIGS. 4and 5.

What is claimed is:

1. In a suction apparatus having suction means for picking up a freeend-portion of a thread on a textile machine wherein the thread isbrought by thread locating means over said suction means and is drawninto said suction means by the suction action thereof, the improvementwhich comprises:

a thread-holder located on the suction means, said threadholdercomprising clamping zones that are biassed towards each other forclamping a thread therebetween; guide means for guiding the end-portionof the thread towards the said clamping zones; and means for pulling theend-portion of the thread, drawn into the suction means, into clampedcondition positioned between the said clamping zones.

2. The suction apparatus of claim 1 in which said suction meanscomprises a suction nozzle having a suction orifice, the clamping zonesare formed by two small clamping plates which bear against each other,said plates being located at the suction orifice of the suction-nozzleand being biassed towards each other, said guide means comprises a pairof generally opposed guide surfaces which, beginning at the clampingzones, diverge from each other to form an opening therebetween; theend-portion of thread to be picked up extends over the suction orificein the freely stretched condition from that side on which the clampingzones are located, and is moved in between the clamping zones by beingpulled back by said means for pulling the thread.

3. The suction apparatus of claim 2 in which said textile machine is aloom, and said means for pulling said thread comprises a threadpull-back device; the thread pull-back device and the suction-nozzlebeing located on opposite sides of the warp-threads on said loom.

4. The suction apparatus of claim 3 in which the thread pullback deviceis arranged between a retaining means for holding the thread and thesuction-nozzle.

5. The suction apparatus of claim 2 in which the clamping plates arearranged approximately in a plane at right-angles to the direction inwhich suction takes place and are positioned to partly overlap eachother, said overlapping portions of the 1 plates forming said clampingzones, the lateral boundary portions of each of the two plates cross ata point of intersection, and said boundary portions comprise the guidemeans which extend in one direction from the point of intersection andform the limits of the clamping zones which extend in the otherdirection from the point of intersection.

6. The suction apparatus of claim 5 in which the two plates are eachsecured on opposite sides of the suction-noule.

7. The suction apparatus of claim 5 in which the upper plate of the twoclamping plates has lateral boundary portions that are rectilinear onboth sides of the point of intersection and the lower plate of the twoclamping plates has lateral boundary portions that have a change ofcourse in the direction extending from the point of intersection in thesense of an increase of the angle defined by the guide surfaces, and inthe other direction extending from the point of intersection, the firstboundary portion of said lower plate extends in at least approximatelythe same direction and then angles at right-angles thereto, to form alimit for one of the clamping zones.

8. The suction apparatus of claim 5 in which the upper plate comprisesferromagnetic material and is biassed towards the lower plate by amagnetic means.

9. The suction apparatus of claim 2 in which the said guide surfaces areprovided by generally inward directed edges of said clamping plates toform an acute angle therebetween so the end-portion of the said threadcan be extended over the suction-nozzle in the freely stretchedcondition in a direction which is at least approximately parallel with astraight line which falls within the said angle formed by the guidesurfaces of said guide means and pass through the apex of this angle.

10. The suction apparatus of claim 2 in which said nozzle has anelongated suction orifice and the clamping zones are located adjacent tothe suction orifice at one end of its lengthwise extent.

1 1. The suction apparatus of claim 2 in which the divergent guidesurfaces form an acute angle.

12. The suction apparatus of claim 1 in which additional means areprovided for individually removing from said thread-holder theend-portions of thread clamped in said holder.

13. The suction apparatus of claim 12 in which said threadholderincludes means for biassing the clamping zones toward each other, andsaid additional means comprises a device for cutting ofi the freeend-portion of each thread and for opening the two clamping zonesthereby overcoming the effect of said biassing means.

14. The suction apparatus of claim 12 in which said additional meanscomprises an auxiliary suction-nozzle which, for the purpose of pickingup a thread, is provided with threader means, said suction meanscomprises a first suction-nozzle,

and the first and the auxiliary suction-nozzles are adapted for movementrelatively to each other so that a first such relative movement caneffect bringing of the thread into the threader means and a second suchrelative movement can effect pulling of the thread out of the firstsuction-noule, with the said second relative movement also effective forcausing an increase in the length of thread required up to the firstsuctionnoule.

15. The suction apparatus of claim 14 in which the auxiliarysuction-nozzle is located at a side of the first suction-nozzle that isadapted to have extended therefrom the end-portion of thread to bepicked up, and the threader means is formed by a portion of theside-wall of the said auxiliary suction-noule that is adjacent to thesaid first suction-nozzle.

16. The suction apparatus of claim 14 in which said textile machine is aloom having a sley and means for forming a shed from warp threadssupplied to the loom, and, in a lateral direction thereof and in thedirection away from the shed. there is first arranged said auxiliarysuction-nozzle followed by the said first suction-nozzle, the auxiliarysuction-nonle being mounted firmly on the loom and the firstsuction-noule adapted to be movable on the sley.

17. The suction apparatus of claim 2 in which, immediately before theclamping zones and extending towards said zones the angle defined by thesaid diverging guide surfaces is diminished by a change in direction ofat least one of the said guide surfaces.

1. In a suction apparatus having suction means for picking up a freeend-portion of a thread on a textile machine wherein the thread isbrought by thread locating means over said suction means and is drawninto said suction means by the suction action thereof, the improvementwhich comprises: a thread-holder located on the suction means, saidthread-holder comprising clamping zones that are biassed towards eachother for clamping a thread therebetween; guide means for guiding theend-portion of the thread towards the said clamping zones; and means forpulling the end-portion of the thread, drawn into the suction means,into clamped condition positioned between the said clamping zones. 2.The suction apparatus of claim 1 in which said suction means comprises asuction nozzle having a suction orifice, the clamping zones are formedby two small clamping plates which bear against each other, said platesbeing located at the suction orifice of the suction-nozzle and beingbiassed towards each other, said guide means comprises a pair ofgenerally opposed guide surfaces which, beginning at the clamping zones,diverge from each other to form an opening therebetween; the end-portionof thread to be picked up extends over the suction orifice in the freelystretched condition from that side on which the clamping zones arelocated, and is moved in between the clamping zones by being pulled backby said means for pulling the thread.
 3. The suction apparatus of claim2 in which said textile machine is a loom, and said means for pullingsaid thread comprises a thread pull-back device; the thread pull-backdevice and the suction-nozzle being located on opposite sides of thewarp-threads on said loom.
 4. The suction apparatus of claim 3 in whichthe thread pull-back device is arranged between a retaining means forholding the thread and the suction-nozzle.
 5. The suction apparatus ofclaim 2 in which the clamping plates are arranged approximately in aplane at right-angles to the direction in which suction takes place andare positioned to partly overlap each other, said overlapping portionsof the plates forming said clamping zones, the lateral boundary portionsof each of the two plates cross at a point of intersection, and saidboundary portions comprise the guide means which extend in one directionfrom the point of intersection and form the limits of the clamping zoneswhich extend in the other direction from the point of intersection. 6.The suction apparatus of claim 5 in which the two plates are eachsecured on opposite sides of the suction-nozzle.
 7. The suctionapparatus of claim 5 in which the upper plate of the two clamping plateshas lateral boundary portions that are rectilinear on both sides of thepoint of intersection and the lower plate of the two clamping plates haslateral boundary portions that have a change of course in the directionextending from the point of intersection in the sense of an increase ofthe angle defined by the guide surfaces, and in the other directionextending from the point of intersection, the first boundary portion ofsaid lower plate extends in at least approximately the same directionand then angles at right-angles thereto, to form a limit for one of theclamping zones.
 8. The suction apparatus of claim 5 in which the upperplate comprises ferromagnetic material and is biassed towards the lowerplate by a magnetic means.
 9. The suction apparatus of claim 2 in whichthe said guide surfaces are provided by generally inward directed edgesof said clamping plates to form an acute angle therebetween so theend-portion of the said thread can be extended over the suction-nozzlein the freely stretched condition in a direction which is at leastapproximately parallel with a straight line which falls within the saidangle formed by the guide surfaces of said guide means and pass throughthe apex of this angle.
 10. The suction apparatus of claim 2 in whichsaid nozzle has an elongated suction orifice and the clamping zones arelocated adjacent to the suction orifice at one end of its lengthwiseextent.
 11. The suction apparatus of claim 2 in which the divergentguide surfaces form an acute angle.
 12. The suction apparatus of claim 1in which additional means are provided for individually removing fromsaid thread-holder the end-portions of thread clamped in said holder.13. The suction apparatus of claim 12 in which said thread-holderincludes means for biassing the clamping zones toward each other, andsaid additional means comprises a device for cutting off the freeend-portion of each thread and for opening the two clamping zonesthereby overcoming the effect of said biassing means.
 14. The suctionapparatus of claim 12 in which said additional means comprises anauxiliary suction-nozzle which, for the purpose of pIcking up a thread,is provided with threader means, said suction means comprises a firstsuction-nozzle, and the first and the auxiliary suction-nozzles areadapted for movement relatively to each other so that a first suchrelative movement can effect bringing of the thread into the threadermeans and a second such relative movement can effect pulling of thethread out of the first suction-nozzle, with the said second relativemovement also effective for causing an increase in the length of threadrequired up to the first suction-nozzle.
 15. The suction apparatus ofclaim 14 in which the auxiliary suction-nozzle is located at a side ofthe first suction-nozzle that is adapted to have extended therefrom theend-portion of thread to be picked up, and the threader means is formedby a portion of the side-wall of the said auxiliary suction-nozzle thatis adjacent to the said first suction-nozzle.
 16. The suction apparatusof claim 14 in which said textile machine is a loom having a sley andmeans for forming a shed from warp threads supplied to the loom, and, ina lateral direction thereof and in the direction away from the shed,there is first arranged said auxiliary suction-nozzle followed by thesaid first suction-nozzle, the auxiliary suction-nozzle being mountedfirmly on the loom and the first suction-nozzle adapted to be movable onthe sley.
 17. The suction apparatus of claim 2 in which, immediatelybefore the clamping zones and extending towards said zones the angledefined by the said diverging guide surfaces is diminished by a changein direction of at least one of the said guide surfaces.